hemstitch
Hemstitch is a handicraft technique with which the fabric edges on linen-binding fabrics (especially white linen such as tablecloths, sheets and aprons) are neatly finished. It is one of the simpler variants of breakthrough work .
The edge of the fabric is folded over twice, as is customary for overcasting hems. Where the first envelope comes to rest, several threads are pulled out parallel to the folded edge. As a result, some of the threads lying across the hem are exposed. The sewing thread is fastened in the folded hem, then the sewing thread is looped around some (usually three to five) of the exposed threads and stabbed through the folded hem again. If you continue this by looping the same number of transverse threads around each time, the transverse threads are bundled together so that small holes are formed along the hem. The sewing thread optically recedes from the holes. This inconspicuousness of the sewing thread was considered particularly desirable in the late 19th and early 20th centuries. Hemstitch went out of fashion during the 20th century.